Influence of prepolymer reaction time in the fabrication of palm kernel oil polyol based shape memory polyurethane

Abstract

Vegetable oil-based shape memory polyurethane (SMPU) has been rapidly developed in the field of advanced polymeric materials due to its unique responsive characteristic. This research aimed to investigate the effect of prepolymer reaction time on the microphase separation, soft segment crystallinity, shape memory, and tensile properties of palm kernel oil polyol (PKO-p)-based SMPU. The SMPU samples were prepared via two-step bulk polymerization process utilizing 4,4-methylenebis (cyclohexyl isocyanate) (HMDI), polycaprolactone diol (PCL) and 1,4-butanediol (BD). The reaction time after the addition of PKO-p varied from 0.5 to 2.5 h in prepolymer synthesis. This reaction time resulted in excellent microphase separation and improve shape memory properties. The Fourier transform infra-red analysis revealed that the degree of microphase separation of the polyurethane elastomer (PUE) increased with increasing prepolymer reaction time. In consequence, the shape fixity behavior of the PUE samples improved. The tensile strength and strain at break of PUE increased with increasing reaction time up to 2.0 h. However, when the reaction time was prolonged to 2.5 h, both values decreased. Thus, the results showed the advantages of using PKO-p, which can minimize the usage of petroleum-based polyol and improve the tensile and shape memory behavior of the PKO-p-based SMPU.

Biobased Polyurethane Adhesives Derived from Vegetable Oil and Rosin for Flexible Packaging Applications

“…The degree of phase separation (DPS) of the biobased PUs can be calculated according to eq 5. 29 The detailed peak deconvolution and DPS values are shown in Figure 3b,…”

“…The peak at 1640 cm –1 is from the hydrogen-bonded – CO groups of the hard segments mixed with the soft segments, and the peak of the free – CO groups from the hard segments is calibrated at 1731 cm –1 . The degree of phase separation (DPS) of the biobased PUs can be calculated according to eq . The detailed peak deconvolution and DPS values are shown in Figure b,d D P S = A H B A F + A normalH normalB = A 1703 + A 1658 + A 1640 A 1731 + A 1703 + A 1658 + A 1640 where A HB is the peak area of the hydrogen-bonded – CO group.…”

“…While the crystallization behavior of PU has been largely investigated by DSC analysis, 33 the observation of crystals within PU using X-ray diffraction has rarely been reported due to the complexity (e.g., microphase separation) of both hard and soft segments. 29 We analyzed the possible crystalline structure (regular packing area of polymer chains) embedded in the biobased PU (the PU/ER and PU/CODM) by higher energy synchrotron radiation. Specifically, WAXS measurements were conducted, and the corresponding 2D patterns and 1D integrated plots are shown in Figure 4.…”

Development of High-Performance Coconut Oil-Based Rigid Polyurethane-Urea Foam: A Novel Sequential Amidation and Prepolymerization Process

“…The p -CDEA was heated below 60 °C under agitation while gradually adding MDI . After 30 min, , the COPUAP was cooled down at ambient temperature, and its viscosity was evaluated using a DV3T viscometer (AMETEK Brookfield, Middleborough, MA) at 25 ± 0.5 °C. The attainment of the torque ranging from 30 to 40% was indicative of the completion of the prepolymerization process …”